Wenjin Li - Atomistic evidence of how force dynamically regulates thiol/disulfide exchange

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      Publication Details (including relevant citation   information):

        Atomistic evidence of how force dynamically regulates   thiol/disulfide exchange

    W Li, F Gräter
    Journal of the American Chemical Society 2010, 132 (47), 16790-16795 (citation: 21)

      Abstract:

        The intricate coupling of mechanical force and chemical   reactivity has been increasingly revealed in recent years by   force spectroscopy experiments on the thiol/disulfide exchange   reaction. We here aimed at elucidating the underlying dynamic   effects of force on the reaction center for the case of disulfide   bond reduction by dithiothreitol at forces of 200−2000 pN, by   combining transition path sampling and quantum/classical   mechanical simulations. Reaction rates and their dependence on   force as quantified by Δxr,   the distance between reactant and transition state, are in good   agreement with experiments but indicate a shift of the transition   state structure at high forces. Indeed, while an associate   SN2   mechanism prevails, force causes a move of the transition state   to a longer length of the cleaving bond and a shorter length of   the forming disulfide bond. Our results highlight the   distribution of force into various degrees of freedom, which   implies that care must be taken when correlating   Δxr with   a single order parameter of the reaction.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/ja104763q